Each year, international surfers compete on Qiantang River, riding the "Silver Dragon" wave, which flows through the city of Hangzhou.

Each autumn, the nine-meter tall tidal bore -- a continuous wave which travels against the current -- surges along the river.

The Qiantang River is just one of a growing number of inner-city surfing spots around the world. Munich's Eisbach River (pictured) has been a popular surfing destination for more than four decades.

The German river is nestled in the heart of Munich's English Gardens, attracting surfers late into the night and a steady stream of onlookers.

Here, surfer Alex Foerderer waits for a train to Eisbach. It was illegal to surf the icy brook until 2010, when the city of Munich allowed experienced surfers to ride the one-meter waves.

Land-locked Switzerland might also seem like an unlikely surfing destination. But popular snowboarding spots have provided an ideal training ground for the next generation of surfers.

Many villages in Switzerland overlook a river, with thrill-seekers now lining up to take the plunge in gushing brooks across the country.

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Surfing the Silver Dragon

Surfing the Silver Dragon

Riding high

Water works

Urban pusuit

Swiss sports

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STORY HIGHLIGHTS

No ocean? No problem. Innovative boarders are surfing city rivers

Munich's Eisbach River attracts young thrill-seekers late into night

China's "Silver Dragon" is world's largest tidal bore

Land-locked Switzerland is home of snowboarders-turned-surfers

Editor's note:Art of Movement is CNN's monthly show exploring the latest innovations in art, culture, science and technology.

(CNN) -- It's 10pm when the young men dressed in wetsuits rock up at Munich's hippest hangout.

There's already a line of people waiting to get in. But it's not a cutting-edge bar or restaurant drawing the huge crowds -- it's a river.

Welcome to the surreal world of urban surfing, where innovative thrill-seekers ride the waves of inner-city rivers.

Munich's Eisbach River -- located in the heart of the German city -- is one of a growing number of urban surfing spots around the world. From China's industrial ports to land-locked Switzerland's stunning waterways, CNN takes a look at this mesmerizing -- and often dangerous -- extreme sport.

Surfers line up for a ride on Munich's Eisbach River.

Dominik Bindl/Getty Images/File

German ingenuity

Munich may be 500 kilometers from the coast, but that hasn't stopped a thriving surfing community springing up around its legendary Eisbach River.

For more than four decades, surfers have been riding the one-meter waves gushing beneath a six-lane highway rumbling with traffic.

Surfing king's search for perfect wave

Even late at night, surfers can be found queuing up to jump in, with onlookers lining the bridge to catch a glimpse of the action below.

But not only is the 460-kilometer river home to an annual festival attracting the best surfers from around the world, it's also the site of a rare wave phenomenon that has been mesmerizing tourists for centuries.

Each autumn, a massive tidal bore -- a wave that travels against the current -- surges up the river. At nine-meters high and traveling at 40 kilometers per hour, the "Silver Dragon," as it is known, is the largest tidal bore in the world and so powerful that only a small number of hefty commercial boats are allowed on the river at the same time.

Now a group of American surfers has launched an annual festival on the river, using jet skis to reach the bore which pounds through the city of Hangzhou.

Towering skyscrapers can be seen looming behind the daring surfers as they ride the murky Silver Dragon.

"Hundreds of thousands of people flock to Hangzhou during the Fall Equinox -- known as the Moon Festival -- every year to stand on the banks and watch this natural phenomenon barrel past," said Glenn Brumage, business director Wabsono International, a company promoting boardsports in China.

"The cityscape, the hundreds of thousands of people lining the banks, the exclusivity and just the fact that it's China all adds to the drama, excitement and allure of surfing the Qiantang."